How to Set up a Water Bath for your FV

[Broomie14]

Cheers im going to have a run with just water to start with make sure i can get the right temp and go from there really

 

[Broomie14]

So i have set up my bath and took it on a trial run and the water around the FV is at the correct temp but it seems the water in the FV is still below 18 on a morning when i check i want to get this right as i dont want it to fail because of the temp even tried the towel trick aswell any thing else i could try ??

 

[flamenco]

I would suggest lagging the whole lot. I use a sleeping bag tied around the water bath and another over the top - so there shouldn't be a lot of heat lost. The water in the bath and the beer in the FV should equalise in temp if they are not fighting against lost heat.

 

[Broomie14]

If i wrap itnin a sleeping bag i wont have much room in the frug for the water or the heater. would putting another heater in and getting the out side water higher warm the inside water do you think

 

[terrym]

If i wrap itnin a sleeping bag i wont have much room in the frug for the water or the heater. would putting another heater in and getting the out side water higher warm the inside water do you think

Why would covering the trug and the FV inside it with insulating blankets, sleeeping bags or whatever else interfere in any way with the water volume in the trug and the heater inside the water?

 

[Broomie14]

The water in the trug is fine but to get a sleeping bag around the fv will be tight against the trug there for cover the heater and i dunno if that will be safe

 

[Broomie14]

I cant put a picture on i dont know how to

 

[flamenco]

You don't need a sleeping bag around the FV. It should go around the (much larger) water bath and another across the top, enclosing all of it. I will take a pic of my set up in a day or two when I'm back home.

 

[Broomie14]

Okay thank you mate

 

[flamenco]

These pics should help? The wire is for the heater and the white cable tie holds the thermometer. The FV is currently holding only water as I'm between brews.

 

[Broomie14]

Ahh i thought people ment to wrap the FV inside the waterbath 😂😂 my bad i have a second heater in and am going to put a king sizw quilt i have spare around it hopefully that will work thank you for the pictures

 

[Richy25]

thanks for a great guide, glad i did the water test 1st.!

Just got my 2nd brewgoing [(manjojacks grapefruit IPA] in an upstairs cold bedroom rarely heated, with a duvet wrapped around. holding about 20 degrees so ill go with that :)

 

[johncrobinson]

About 20c will be just fine.

Have to say though as an old timer I thought problems in keeping a warm cosy home were a thing of the past.

Seems what goes around comes around.

 

[Richy25]

1. This Tek works perfectly got it sitting at 19 c now so good as my house is cold %

 

[MikeAdz]

does the water in the bath need to be the same level as the water in the FV? if the water is below the level of the FV will it be inconsistent tempretures inside the FV?

 

[kelper]

Just make sure the aquarium heater stat can be turned down below 20C. Luckily I already had an Inkbird controller. I had to turn the heat setting down to 17 initially because the fermentation was giving off quite a lot of heat. With water at 18 it reached 21. Obviously, as the fermentation slows down the water bath will need to be warmer than the FV.

 

[terrym]

does the water in the bath need to be the same level as the water in the FV? if the water is below the level of the FV will it be inconsistent tempretures inside the FV?

I usually add about 10 litres of water to the bath. Then when the FV is put into the bath that means my 50w heater is fully immersed, but the water level in the bath is about 50mm below the level of the beer. If you have the two levels about the same or worse the water level in the bath higher than beer level there is a likelihood of the FV floating which clearly is to be avoided.
And for sure you will get small temperature differences in the beer when the fermentation is going strong due to the exotherm and convection currents, in whatever method you use, but in my view that is not a problem provided you are operating within the recommended yeast limits. Others may disagree.

 

[kelper]

Just to add to Terry's excellent thread, I've found that my 33 litre FV easily holds my 25 litre FV. I put the aquarium heater on the bottom of the larger FV and protected it with three stones from the garden. I added enough water to match the level of the inner FV as I believe a larger water volume will change its temperature nice and slowly, helping to prevent any overshoot. I'm toying with the idea of putting the Inkbird temperature probe into the inner FV but I need to find a bung that is snug around the cable but will pass the probe.

 

[Rogermort]

How do you take samples for hydrometer tests if your fv tap is under water?

 

[Chippy_Tea]

Open the lid and either drop the hydrometer into the FV or use something like a turkey baster to fill your trial jar.